A tunnel field effect transistor (TFET) is an LSI-applicable, low-power consumption transistor having different type between a source and a drain of a semiconductor, and an asymmetric diffusion layer. Since a sub-threshold swing (hereinafter, referred to as SS) steeper than that of a MOSFET can be obtained, TFET can realize a high on current and a low off current.
However, with the TFET having the steep SS, there are large variations in the off current. With the MOSFET, the variations in the off current can be restrained by regulating a threshold voltage by a body effect. However, since the TFET has a different impurity profile between the source and the drain, it is not possible to add a substrate electrode. Therefore, the threshold voltage of the TFET, which is constituted on a bulk substrate, is determined by the thickness of a gate insulating film (i.e., effective oxide thickness (EOT)) or a structural parameter such as junction abruptness of an impurity diffusion layer, and it is not possible to regulate the threshold voltage after completion of a device.